Relationship and field domain editing error

[hefniraera]

What is the bug or the crash?

In the Browser Panel, editing existing relationships and field domains does not actually save any changes. When I edit a relationship or a field domain and click OK, QGIS shows a success message, but nothing is updated, the settings always revert to their original values when I reopen the edit dialog. A bug?

Steps to reproduce the issue

right click relationship or field domain you've created --> edit

Versions

QGIS version	3.99.0-Master
QGIS code revision	21b3aa880ba
Libraries
Qt version	6.8.1
Python version	3.12.12
GDAL version	3.13.0dev-c959ec2724 (Compiled) 3.13.0dev-025c9cb528 (Running)
PROJ version	9.7.1
EPSG Registry database version	v12.029 (2025-10-03)
GEOS version	3.13.1-CAPI-1.19.2
SFCGAL version	No support
SQLite version	3.50.4
PDAL version	2.9.0
PostgreSQL client version	17.3
SpatiaLite version	5.1.0
QWT version	6.3.0
QScintilla2 version	2.14.1
OS version	Windows 11 Version 25H2
This copy of QGIS writes debugging output.
Active Python plugins
db_manager	0.1.20
grassprovider	2.12.99
MetaSearch	0.3.6
processing	2.12.99

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

No response

[agiudiceandrea]

Ping @JanCaha.

[JanCaha]

I cannot replicate this. See the screencast. @hefniraera can you do a screencast where it does not work?

[agiudiceandrea]

@hefniraera , please also provide the layer's file.

[hefniraera]

InfrastructureMapper_test.zip

My question was, does the update only work internally? Suppose I change 'split policy' from default to certain value. It does notify us the successful update but when we reopen the editing dialog, it reverts back to initial value. @agiudiceandrea @JanCaha

[JanCaha]

Ok, that makes more sense. Those cannot change as GPKG as format does not support either SplitPolicy or MergePolicy. Within GDAL those exist only for FileGDB driver.

So these are not stored and thus always show the default value.

[hefniraera]

Ok, that makes more sense. Those cannot change as GPKG as format does not support either SplitPolicy or MergePolicy. Within GDAL those exist only for FileGDB driver.

So these are not stored and thus always show the default value.

Thanks, that helps.

But I might still be misunderstanding something here: for geopackage the split/merge policy fields dont get stored, dont get applied, and gpkg itself doesn't support these policies in the first place.

If these options only become meaningful for FileGDB, and FileGDB isn't even exposed in the browser by default. Then from the user side they look like controls that will never have any effect. 🤔

[NyakudyaA]

Ok, that makes more sense. Those cannot change as GPKG as format does not support either SplitPolicy or MergePolicy. Within GDAL those exist only for FileGDB driver.

So these are not stored and thus always show the default value.

Shouldn't this then be changed to a feature request where the policies are greyed out for the GPKG and active for FileGDB to have more clarity for users?

[hefniraera]

Any advice on how we might proceed with this qgis/QGIS-Documentation#10534 ? @DelazJ

[JanCaha]

From my point of view, there is no simple way to do this problem as it does not seem that GDAL would provide a way to check if driver actually supports those policies. That might be a reason why this is always available even though in some cases (like GPKG) it has no effect.

[hefniraera]

This problem also occurs in relationship editing. Updating any value has no effect. Is it also related to GDAL or something? Same as split/merge policies case?

[DelazJ]

If these options only become meaningful for FileGDB, and FileGDB isn't even exposed in the browser by default. Then from the user side they look like controls that will never have any effect.

I fully agree that these controls shouldn't be exposed when irrelevant.
@nyalldawson @rouault Any idea if there are some capabilities we can check to decide whether to show or not these merge/split policies? thanks